Publications

global analysis of asymmetric rna enrichment in oocytes reveals low conservation between closely related xenopus species.	rnas that localize to the vegetal cortex during xenopus laevis oogenesis have been reported to function in germ layer patterning, axis determination, and development of the primordial germ cells. here we report on the genome-wide, comparative analysis of differentially localizing rnas in xenopus laevis and xenopus tropicalis oocytes, revealing a surprisingly weak degree of conservation in respect to the identity of animally as well as vegetally enriched transcripts in these closely related speci ...	2015	26337391
hspa9 is required for pronephros specification and formation in xenopus laevis.	development of the pronephros in xenopus laevis is largely dependent on retinoic acid signaling at the time of kidney field specification with the simultaneous occurrence of a necessary calcium signaling. at the crossroads of these two signaling pathways, we studied the role of hspa9 (heat shock 70 kda protein 9) encoding a mitochondrial chaperone in pronephros development.	2015	26335666
sensory-evoked spiking behavior emerges via an experience-dependent plasticity mechanism.	the ability to generate action potentials (spikes) in response to synaptic input determines whether a neuron participates in information processing. how a developing neuron becomes an active participant in a circuit or whether this process is activity dependent is not known, especially as spike-dependent plasticity mechanisms would not be available to non-spiking neurons. here we use the optic tectum of awake xenopus laevis tadpoles to determine how a neuron becomes able to generate sensory-driv ...	2015	26335647
copy number variation and genetic diversity of mhc class iib alleles in an alien population of xenopus laevis.	xenopus laevis (the african clawed frog), which originated through hybridisation and whole genome duplication, has been used as a model for genetics and development for many years, but surprisingly little is known about immune gene variation in natural populations. the purpose of this study was to use an isolated population of x. laevis that was introduced to wales, uk in the past 50 years to investigate how variation at the mhc compares to that at other loci, following a severe population bottl ...	2015	26329765
characterization of ticlopidine-induced developmental and teratogenic defects in xenopus embryos and human endothelial cells.	ticlopidine is an anti-platelet drug that inhibits platelet aggregation via the functional alteration of platelet membranes. however, the mechanism underlying the adverse developmental effects of ticlopidine has not been clearly demonstrated. in this study, we evaluated the developmental toxicity and teratogenicity of ticlopidine on xenopus laevis embryos and in human umbilical vein endothelial cells (huvecs) using a frog embryo teratogenesis assay-xenopus (fetax) and blood and lymph vessel form ...	2015	26327247
glutathione release through connexin hemichannels: implications for chemical modification of pores permeable to large molecules.	cysteine-scanning mutagenesis combined with thiol reagent modification is a powerful method with which to define the pore-lining elements of channels and the changes in structure that accompany channel gating. using the xenopus laevis oocyte expression system and two-electrode voltage clamp, we performed cysteine-scanning mutagenesis of several pore-lining residues of connexin 26 (cx26) hemichannels, followed by chemical modification using a methanethiosulfonate (mts) reagent, to help identify t ...	2015	26324677
prepatterning and patterning of the thalamus along embryonic development of xenopus laevis.	previous developmental studies of the thalamus (alar part of the diencephalic prosomere p2) have defined the molecular basis for the acquisition of the thalamic competence (preparttening), the subsequent formation of the secondary organizer in the zona limitans intrathalamica, and the early specification of two anteroposterior domains (rostral and caudal progenitor domains) in response to inducing activities and that are shared in birds and mammals. in the present study we have analyzed the embr ...	2015	26321920
aquaporins mediate silicon transport in humans.	in animals, silicon is an abundant and differentially distributed trace element that is believed to play important biological functions. one would thus expect silicon concentrations in body fluids to be regulated by silicon transporters at the surface of many cell types. curiously, however, and even though they exist in plants and algae, no such transporters have been identified to date in vertebrates. here, we show for the first time that the human aquaglyceroporins, i.e., aqp3, aqp7, aqp9 and ...	2015	26313002
effect of a grin2a de novo mutation associated with epilepsy and intellectual disability on nmda receptor currents and mg(2+) block in cultured primary cortical neurons.	background grin2a encodes the glun2a subunit of the nmda receptor (nmdar), an ionotropic glutamate receptor that has important roles in synaptogenesis and synaptic plasticity. some individuals with early onset epilepsies and intellectual disability carry heterozygous missense mutations in this gene, including a de-novo mutation in the receptor pore region (glun2a(n615k)). we hypothesised that this mutation underlies the carrier's brain disorder and sought to explore its functional consequences.	2015	26312887
prediction of functionally important phospho-regulatory events in xenopus laevis oocytes.	the african clawed frog xenopus laevis is an important model organism for studies in developmental and cell biology, including cell-signaling. however, our knowledge of x. laevis protein post-translational modifications remains scarce. here, we used a mass spectrometry-based approach to survey the phosphoproteome of this species, compiling a list of 2636 phosphosites. we used structural information and phosphoproteomic data for 13 other species in order to predict functionally important phospho- ...	2015	26312481
targeted inhibition of snail activity in breast cancer cells by using a co(iii) -ebox conjugate.	the transition from a non-invasive to an invasive phenotype is an essential step in tumor metastasis. the snail family of transcription factors (tfs) is known to play a significant role in this transition. these tfs are zinc fingers that bind to the caggtg ebox consensus sequence. co(iii) -ebox is a cobalt(iii) complex attached to an ebox oligonucleotide that confers specificity towards snail tfs. co(iii) -ebox has been shown to inhibit snail-mediated embryonic neural crest development in xenopu ...	2015	26305708
the neonicotinoid imidacloprid, and the pyrethroid deltamethrin, are antagonists of the insect rdl gaba receptor.	a mutation in the second transmembrane domain of the gaba receptor subunit, rdl, is associated with resistance to insecticides such as dieldrin and fipronil. molecular cloning of rdl cdna from a strain of the malaria mosquito, anopheles gambiae, which is highly resistant to dieldrin revealed this mutation (a296g) as well as another mutation in the third transmembrane domain (t345m). wild-type, a296g, t345m and a296g + t345m homomultimeric rdl were expressed in xenopus laevis oocytes and their se ...	2015	26296809
metamorphic remodeling of the olfactory organ of the african clawed frog, xenopus laevis.	the amphibian olfactory system undergoes massive remodeling during metamorphosis. the transition from aquatic olfaction in larvae to semiaquatic or airborne olfaction in adults requires anatomical, cellular, and molecular modifications. these changes are particularly pronounced in pipidae, whose adults have secondarily adapted to an aquatic life style. in the fully aquatic larvae of xenopus laevis, the main olfactory epithelium specialized for sensing water-borne odorous substances lines the pri ...	2016	26294036
direct recording of trans-plasma membrane electron currents mediated by a member of the cytochrome b561 family of soybean.	trans-plasma membrane electron transfer is achieved by b-type cytochromes of different families, and plays a fundamental role in diverse cellular processes involving two interacting redox couples that are physically separated by a phospholipid bilayer, such as iron uptake and redox signaling. despite their importance, no direct recordings of trans-plasma membrane electron currents have been described in plants. in this work, we provide robust electrophysiological evidence of trans-plasma membran ...	2015	26282237
glutamate cycling may drive organic anion transport on the basal membrane of human placental syncytiotrophoblast.	the organic anion transporter oat4 (slc22a11) and organic anion transporting polypeptide oatp2b1 (slco2b1) are expressed in the basal membrane of the placental syncytiotrophoblast. these transporters mediate exchange whereby uptake of one organic anion is coupled to efflux of a counter-ion. in placenta, these exchangers mediate placental uptake of substrates for oestrogen synthesis as well as clearing waste products and xenobiotics from the fetal circulation. however, the identity of the counter ...	2015	26277985
xenopus pkdcc1 and pkdcc2 are two new tyrosine kinases involved in the regulation of jnk dependent wnt/pcp signaling pathway.	protein kinase domain containing, cytoplasmic (pkdcc) is a protein kinase which has been implicated in longitudinal bone growth through regulation of chondrocytes formation. nevertheless, the mechanism by which this occurs remains unknown. here, we identified two new members of the pkdcc family, pkdcc1 and pkdcc2 from xenopus laevis. interestingly, our knockdown experiments revealed that these two proteins are both involved on blastopore and neural tube closure during gastrula and neurula stages ...	2015	26270962
identification of genes expressed in the migrating primitive myeloid lineage of xenopus laevis.	during primitive hematopoiesis in xenopus, cebpa and spib expressing myeloid cells emerge from the anterior ventral blood island. primitive myeloid cells migrate throughout the embryo and are critical for immunity, healing, and development. although definitive hematopoiesis has been studied extensively, molecular mechanisms leading to the migration of primitive myelocytes remain poorly understood. we hypothesized these cells have specific extracellular matrix modifying and cell motility gene exp ...	2016	26264370
the small heat shock protein, hsp30, is associated with aggresome-like inclusion bodies in proteasomal inhibitor-, arsenite-, and cadmium-treated xenopus kidney cells.	in the present study, treatment of xenopus laevis a6 kidney epithelial cells with the proteasomal inhibitor, mg132, or the environmental toxicants, sodium arsenite or cadmium chloride, induced the accumulation of the small heat shock protein, hsp30, in total and in both soluble and insoluble protein fractions. immunocytochemical analysis revealed the presence of relatively large hsp30 structures primarily in the perinuclear region of the cytoplasm. all three of the stressors promoted the formati ...	2015	26260897
fluorescent ratiometric ph indicator sypher2: applications in neuroscience and regenerative biology.	sypher is a genetically encoded fluorescent ph-indicator with a ratiometric readout, suitable for measuring fast intracellular ph shifts. however, the relatively low brightness of the indicator limits its use.	2015	26259819
a screening assay for thyroid hormone signaling disruption based on thyroid hormone-response gene expression analysis in the frog pelophylax nigromaculatus.	amphibian metamorphosis provides a wonderful model to study the thyroid hormone (th) signaling disrupting activity of environmental chemicals, with xenopus laevis as the most commonly used species. this study aimed to establish a rapid and sensitive screening assay based on th-response gene expression analysis using pelophylax nigromaculatus, a native frog species distributed widely in east asia, especially in china. to achieve this, five candidate th-response genes that were sensitive to t3 ind ...	2015	26257357
cell cycle synchronization in xenopus egg extracts.	many important discoveries in cell cycle research have been made using cell-free extracts prepared from the eggs of the south african clawed frog xenopus laevis. these extracts efficiently support the key nuclear functions of the eukaryotic cell cycle in vitro under apparently the same controls that exist in vivo. the xenopus cell-free system is therefore uniquely suited to the study of the mechanisms, dynamics and integration of cell cycle regulated processes at a biochemical level. here, we de ...	2016	26254920
pseudouridine in mrna: incorporation, detection, and recoding.	it has long been known that pseudouridine (ψ) is the most abundant modified nucleotide in stable rnas, including trna, rrna, and snrna. recent studies using massive parallel sequencing have uncovered the presence of hundreds of ψs in mrnas as well. in eukaryotes and archaea, rna pseudouridylation is introduced predominantly by box h/aca rnps, rna-protein complexes each consisting of a single rna moiety and four core proteins. it has been well established that ψ plays an essential role in regulat ...	2015	26253972
the human acid-sensing ion channel asic1a: evidence for a homotetrameric assembly state at the cell surface.	the chicken acid-sensing ion channel asic1 has been crystallized as a homotrimer. we address here the oligomeric state of the functional asic1 in situ at the cell surface. the oligomeric states of functional asic1a and mutants with additional cysteines introduced in the extracellular pore vestibule were resolved on sds-page. the functional asic1 complexes were stabilized at the cell surface of xenopus laevis oocytes or cho cells either using the sulfhydryl crosslinker bmoe, or sodium tetrathiona ...	2015	26252376
asymmetries in kinesin-2 and cytoplasmic dynein contributions to melanosome transport.	the mechanisms involved in bidirectional transport along microtubules remain largely unknown. we explored the collective action of kinesin-2 and dynein motors during transport of melanosomes in xenopus laevis melanophores. these motors are attached to organelles through accessory proteins establishing a complex molecular linker. we determined both the stiffness of this linker and the organelles speed and observed that these parameters depended on the organelle size and cargo direction. our resul ...	2015	26247430
g protein-coupled receptors flop1 and flop2 inhibit wnt/β-catenin signaling and are essential for head formation in xenopus.	patterning of the vertebrate anterior-posterior axis is regulated by the coordinated action of growth factors whose effects can be further modulated by upstream and downstream mediators and the cross-talk of different intracellular pathways. in particular, the inhibition of the wnt/β-catenin signaling pathway by various factors is critically required for anterior specification. here, we report that flop1 and flop2 (flop1/2), g protein-coupled receptors related to gpr4, contribute to the regulati ...	2015	26244992
fertilization competence of the egg-coating envelope is regulated by direct interaction of dicalcin and gp41, the xenopus laevis zp3.	fertilization begins with species-restricted interaction of sperm and the egg-coating envelope, which includes a three-dimensional meshwork of filaments composed of glycoproteins (called zp proteins). growing evidence has unveiled the molecular nature of zp proteins; however, the structural property conferring fertilization competence to the egg-coating envelope remains unknown. here, we show the molecular mechanism that mediates direct interaction between dicalcin, a novel fertilization-suppres ...	2015	26243547
astrocytes phagocytose focal dystrophies from shortening myelin segments in the optic nerve of xenopus laevis at metamorphosis.	oligodendrocytes can adapt to increases in axon diameter through the addition of membrane wraps to myelin segments. here, we report that myelin segments can also decrease their length in response to optic nerve (on) shortening during xenopus laevis metamorphic remodeling. em-based analyses revealed that myelin segment shortening is accomplished by focal myelin-axon detachments and protrusions from otherwise intact myelin segments. astrocyte processes remove these focal myelin dystrophies using k ...	2015	26240339
kinesin family 17 (osmotic avoidance abnormal-3) is dispensable for photoreceptor morphology and function.	in caenorhabditis elegans, homodimeric [kinesin family (kif) 17, osmotic avoidance abnormal-3 (osm-3)] and heterotrimeric (kif3) kinesin-2 motors are required to establish sensory cilia by intraflagellar transport (ift) where kif3 and kif17 cooperate to build the axoneme core and kif17 builds the distal segments. however, the function of kif17 in vertebrates is unresolved. we expressed full-length and motorless kif17 constructs in mouse rod photoreceptors using adeno-associated virus in xenopus ...	2015	26229057
do nanoparticle physico-chemical properties and developmental exposure window influence nano zno embryotoxicity in xenopus laevis?	the growing global production of zinc oxide nanoparticles (znonps) suggests a realistic increase in the environmental exposure to such a nanomaterial, making the knowledge of its biological reactivity and its safe-by-design synthesis mandatory. in this study, the embryotoxicity of znonps (1-100 mg/l) specifically synthesized for industrial purposes with different sizes, shapes (round, rod) and surface coatings (peg, pvp) was tested using the frog embryo teratogenesis assay-xenopus (fetax) to ide ...	2015	26225989
regulation of growth rate and developmental timing by xenopus thyroid hormone receptor α.	thyroid hormone (th) is critical for vertebrate postembryonic development, a period around birth in mammals when plasma th levels are high. interestingly, th receptors (trs), especially trα, are expressed prior to the synthesis and secretion of zygotic th, suggesting the existence of unliganded tr during development. however, the role of unliganded tr during mammalian development has been difficult to study, in part due to the relatively weak phenotype of tr knockout mice. amphibian metamorphosi ...	2016	26219216
atp4 and ciliation in the neuroectoderm and endoderm of xenopus embryos and tadpoles.	during gastrulation and neurulation, foxj1 expression requires atp4a-dependent wnt/β-catenin signaling for ciliation of the gastrocoel roof plate (walentek et al. cell rep. 1 (2012) 516-527.) and the mucociliary epidermis (walentek et al. dev. biol. (2015)) of xenopus laevis embryos. these data suggested that atp4a and wnt/β-catenin signaling regulate foxj1 throughout xenopus development. here we analyzed whether foxj1 expression was also atp4a-dependent in other ciliated tissues of the developi ...	2015	26217756
coexistence of y, w, and z sex chromosomes in xenopus tropicalis.	homomorphic sex chromosomes and rapid turnover of sex-determining genes can complicate establishing the sex chromosome system operating in a given species. this difficulty exists in xenopus tropicalis, an anuran quickly becoming a relevant model for genetic, genomic, biochemical, and ecotoxicological research. despite the recent interest attracted by this species, little is known about its sex chromosome system. direct evidence that females are the heterogametic sex, as in the related species xe ...	2015	26216983
how does the xenopus laevis embryonic cell cycle avoid spatial chaos?	theoretical studies have shown that a deterministic biochemical oscillator can become chaotic when operating over a sufficiently large volume and have suggested that the xenopus laevis cell cycle oscillator operates close to such a chaotic regime. to experimentally test this hypothesis, we decreased the speed of the post-fertilization calcium wave, which had been predicted to generate chaos. however, cell divisions were found to develop normally, and eggs developed into normal tadpoles. motivate ...	2015	26212326
aspergillus glaucus aquaglyceroporin gene glpf confers high osmosis tolerance in heterologous organisms.	aquaglyceroporins (glpfs) that transport glycerol along with water and other uncharged solutes are involved in osmoregulation in myriad species. fungal species form a large group of eukaryotic organisms, and their glpfs may be diverse, exhibiting various activities. however, few filamentous fungal glpfs have been biologically investigated. here, a glpf gene from the halophilic fungus aspergillus glaucus (agglpf) was verified to be a channel of water or glycerol in xenopus laevis oocytes and was ...	2015	26209670
xenopus lap2β protein knockdown affects location of lamin b and nucleoporins and has effect on assembly of cell nucleus and cell viability.	xenopus lap2β protein is the single isoform expressed in xtc cells. the protein localizes on heterochromatin clusters both at the nuclear envelope and inside a cell nucleus. the majority of xlap2β fraction neither colocalizes with tpx2 protein during interphase nor can be immunoprecipitated with xlap2β antibody. knockdown of the xlap2β protein expression in xtc cells by synthetic sirna and plasmid encoded sirna resulted in nuclear abnormalities including changes in shape of nuclei, abnormal chro ...	2016	26209045
light sensitivity in a vertebrate mechanoreceptor?	using immunohistochemistry and western blot analysis, we demonstrate that melanopsin is localised in cells around the central pore of lateral line neuromasts in the african clawed frog, xenopus laevis. since melanopsin is a known photoreceptor pigment with diverse functions in vertebrates, we suggest that the lateral line of xenopus laevis, which is primarily a mechanoreceptor, might also be light sensitive. potential functions of such photosensitivity are discussed, including its role in mediat ...	2015	26206352
concentration-response relationship of the α7 nicotinic acetylcholine receptor agonist frm-17874 across multiple in vitro and in vivo assays.	pharmacological activation of α7 nicotinic acetylcholine receptors (α7 nachrs) may improve cognition in schizophrenia and alzheimer's disease. the present studies describe an integrated pharmacological analysis of the effects of frm-17874, an analogue of encenicline, on α7 nachrs in vitro and in behavioral and neurophysiological assays relevant to cognitive function. frm-17874 demonstrated high affinity binding to human α7 nachrs, displacing [(3)h]-methyllacaconitine (ki=4.3nm). in xenopus laevi ...	2015	26206187
the n-methyl-d-aspartate receptor's neglected subunit - glun1 matters under normal and hyperbaric conditions.	professional deep-water divers exposed to hyperbaric pressure (hp) above 1.1 mpa develop high-pressure neurological syndrome, which is associated with central nervous system hyperexcitability. it was previously reported that hp augments n-methyl-d-aspartate receptor (nmdar) synaptic responses, increases neuronal excitability, and potentially causes irreversible neuronal damage. in addition, we have reported that hp (10.1 mpa) differentially affects ionic currents, measured by the two-electrode v ...	2015	26202884
kruppel-like factor family genes are expressed during xenopus embryogenesis and involved in germ layer formation and body axis patterning.	kruppel-like factors (klfs) are a family of transcription factors consisting of 17 members in mammals, klf1-klf17, which are involved in fundamental cellular physiological procedures, such as cell proliferation, differentiation, and apoptosis. however, their functions in embryonic development have been poorly understood. our previous study has demonstrated that the pluripotency factor klf4 participates in germ layer formation and axis patterning of xenopus embryos by means of the regulation of k ...	2015	26198170
selective depolarization of transmembrane potential alters muscle patterning and muscle cell localization in xenopus laevis embryos.	the correct anatomical placement and precise determination of specific cell types is required for the establishment of normal embryonic patterning. understanding these processes is also important for progress in regenerative medicine and cancer biology. transmembrane voltage gradients across embryonic tissues can mediate cellular communication to regulate the processes of proliferation, migration, and differentiation. our past work showed that selective depolarization of an endogenous instructor ...	2015	26198143
local and long-range endogenous resting potential gradients antagonistically regulate apoptosis and proliferation in the embryonic cns.	bioelectric signals, particularly transmembrane voltage potentials (vmem), play an important role in large-scale patterning during embryonic development. endogenous bioelectric gradients across tissues function as instructive factors during eye, brain, and other morphogenetic processes. an important and still poorly-understood aspect is the control of cell behaviors by the voltage states of distant cell groups. here, experimental alteration of endogenous vmem was induced in xenopus laevis embryo ...	2015	26198142
functional integration of mrna translational control programs.	regulated mrna translation plays a key role in control of cell cycle progression in a variety of physiological and pathological processes, including in the self-renewal and survival of stem cells and cancer stem cells. while targeting mrna translation presents an attractive strategy for control of aberrant cell cycle progression, mrna translation is an underdeveloped therapeutic target. regulated mrnas are typically controlled through interaction with multiple rna binding proteins (rbps) but the ...	2015	26197342
comparative analysis of cartilage marker gene expression patterns during axolotl and xenopus limb regeneration.	axolotls (ambystoma mexicanum) can completely regenerate lost limbs, whereas xenopus laevis frogs cannot. during limb regeneration, a blastema is first formed at the amputation plane. it is thought that this regeneration blastema forms a limb by mechanisms similar to those of a developing embryonic limb bud. furthermore, xenopus laevis frogs can form a blastema after amputation; however, the blastema results in a terminal cone-shaped cartilaginous structure called a "spike." the causes of this p ...	2015	26186213
flexible subunit stoichiometry of functional human p2x2/3 heteromeric receptors.	the aim of the present work was to clarify whether heterotrimeric p2x2/3 receptors have a fixed subunit stoichiometry consisting of one p2x2 and two p2x3 subunits as previously suggested, or a flexible stoichiometry containing also the inverse subunit composition. for this purpose we transfected hek293 cells with p2x2 and p2x3 encoding cdna at the ratios of 1:2 and 4:1, and analysed the biophysical and pharmacological properties of the generated receptors by means of the whole-cell patch-clamp t ...	2015	26184350
annexin a3 regulates early blood vessel formation.	annexins are a large family of calcium binding proteins that associate with cell membrane phospholipids and are involved in various cellular processes including endocytosis, exocytosis and membrane-cytoskeletal organization. despite studies on numerous annexin proteins, the function of annexin a3 (anxa3) is largely unknown. our studies identify anxa3 as a unique marker of the endothelial and myeloid cell lineages of xenopus laevis during development. anxa3 transcripts are also detected in endoth ...	2015	26182056
the mutation p.t613a in the pore helix of the kv 11.1 potassium channel is associated with long qt syndrome.	loss-of-function mutations in the voltage gated potassium channel kv 11.1 have been associated with the long qt syndrome (lqts) type 2. we identified the p.t613a mutation in kv 11.1 in a family with lqts. t613a is located in the outer part of the pore helix, a structure that is involved in c-type inactivation. here we characterize the effect of p.t613a on the functional properties of kv 11.1.	2015	26173150
retention of duplicated itam-containing transmembrane signaling subunits in the tetraploid amphibian species xenopus laevis.	the itam-bearing transmembrane signaling subunits (tss) are indispensable components of activating leukocyte receptor complexes. the tss-encoding genes map to paralogous chromosomal regions, which are thought to arise from ancient genome tetraploidization(s). to assess a possible role of tetraploidization in the tss evolution, we studied tss and other functionally linked genes in the amphibian species xenopus laevis whose genome was duplicated about 40 myr ago. we found that x. laevis has retain ...	2015	26170006
dehydration triggers differential microrna expression in xenopus laevis brain.	african clawed frogs, xenopus laevis, although primarily aquatic, have a high tolerance for dehydration, being capable of withstanding the loss of up to 32-35% of total water body water. recent studies have shown that micrornas play a role in the response to dehydration by the liver, kidney and ventral skin of x. laevis. micrornas act by modulating the expression of mrna transcripts, thereby affecting diverse biochemical pathways. in this study, 43 micrornas were assessed in frog brains comparin ...	2015	26169019
aquaporins contribute to aba-triggered stomatal closure through ost1-mediated phosphorylation.	stomatal movements in response to environmental stimuli critically control the plant water status. although these movements are governed by osmotically driven changes in guard cell volume, the role of membrane water channels (aquaporins) has remained hypothetical. assays in epidermal peels showed that knockout arabidopsis thaliana plants lacking the plasma membrane intrinsic protein 2;1 (pip2;1) aquaporin have a defect in stomatal closure, specifically in response to abscisic acid (aba). aba ind ...	2015	26163575
testing the evolutionary conservation of vocal motoneurons in vertebrates.	medullary motoneurons drive vocalization in many vertebrate lineages including fish, amphibians, birds, and mammals. the developmental history of vocal motoneuron populations in each of these lineages remains largely unknown. the highly conserved transcription factor paired-like homeobox 2b (phox2b) is presumed to be expressed in all vertebrate hindbrain branchial motoneurons, including laryngeal motoneurons essential for vocalization in humans. we used immunohistochemistry and in situ hybridiza ...	2016	26160673
evolutionary trend for metamery reduction and gonad shortening in anurans revealed by comparison of gonad development.	the gonads develop as the metameric mesodermal structures at the ventral surface of the mesonephroi. to study the evolutionary trends for anuran gonads, we performed comparative analysis of three species from the basal paraphyletic group - archaeobatrachia (bombina bombina, xenopus laevis, pelobates fuscus) and five species from more derived monophyletic neobatrachia group (hyla arborea, bufotes viridis, rana dalmatina, rana arvalis, rana temporaria). light and scanning electron microscopy analy ...	2014	26154333
comparative expression analysis of cysteine-rich intestinal protein family members crip1, 2 and 3 during xenopus laevis embryogenesis.	members of the cysteine-rich intestinal protein (crip) family belong to the group 2 lim proteins. crip proteins are widely expressed in adult mammals but their expression profile and function during embryonic development are still mostly unknown. in this study, we have described for the first time the spatio-temporal expression pattern of the three family members crip1, crip2 and crip3 during xenopus laevis embryogenesis by rt-pcr and whole mount in situ hybridization approaches. we observed tha ...	2014	26154325
epithelial cell division in the xenopus laevis embryo during gastrulation.	how vertebrate epithelial cells divide in vivo and how the cellular environment influences cell division is currently poorly understood. a sine qua non condition to study cell division in situ is the ease of observation of cell division. this is fulfilled in the xenopus embryo at the gastrula stage where polarized epithelial cells divide with a high frequency at the surface of the organism. recently, using this model system, we have shown that epithelial cells divide by asymmetric furrowing and ...	2014	26154319
control of timing of embryonic m-phase entry and exit is differentially sensitive to cdk1 and pp2a balance.	harmonious embryo development requires precise coordination between the timing of the cell cycle and the developmental program. cyclin accumulation determines the timing of the cell cycle m-phase entry and its degradation determines the timing of the m-phase exit. it is well known that cdk1 and pp2a also govern m-phase entry. however, it is unknown how this kinase and phosphatase regulate the precise timing of events at the beginning of the m-phase and how they cooperate with cyclin metabolism. ...	2014	26154318
mechanisms of amphibian macrophage development: characterization of the xenopus laevis colony-stimulating factor-1 receptor.	macrophage-lineage cells are indispensable to vertebrate homeostasis and immunity. in turn, macrophage development is largely regulated through colony-stimulating factor-1 (csf1) binding to its cognate receptor (csf1r). to study amphibian monopoiesis, we identified and characterized the x. laevis csf1r cdna transcript. quantitative analysis revealed that csf1r tissue gene expression increased with x. laevis development, with greatest transcript levels detected in the adult lung, spleen and liver ...	2014	26154317
developing xenopus embryos recover by compacting and expelling single wall carbon nanotubes.	single wall carbon nanotubes are high aspect ratio nanomaterials being developed for use in materials, technological and biological applications due to their high mechanical stiffness, optical properties and chemical inertness. because of their prevalence, it is inevitable that biological systems will be exposed to nanotubes, yet studies of the effects of nanotubes on developing embryos have been inconclusive and are lacking for single wall carbon nanotubes exposed to the widely studied model or ...	2016	26153061
developmental role of plk4 in xenopus laevis and danio rerio: implications for seckel syndrome.	the polo-like kinases are a family of conserved serine/threonine kinases that play multiple roles in regulation of the cell cycle. unlike its four other family members, the role of plk4 in embryonic development has not been well characterized. in mice, plk4(-)(/)(-) embryos arrest at e7.5, just prior to the initiation of somitogenesis. this has led to the hypothesis that plk4 expression may be essential to somitogenesis. recently characterized human mutations lead to seckel syndrome. riboprobe i ...	2015	26150138
functional analysis of phosphorylation of the mitotic centromere-associated kinesin by aurora b kinase in human tumor cells.	mitotic centromere-associated kinesin (mcak) is the best characterized member of the kinesin-13 family and plays important roles in microtubule dynamics during mitosis. its activity and subcellular localization is tightly regulated by an orchestra of mitotic kinases, such as aurora b. it is well known that serine 196 of mcak is the major phosphorylation site of aurora b in xenopus leavis extracts and that this phosphorylation regulates its catalytic activity and subcellular localization. in the ...	2015	26148251
lack of phosphomannomutase 2 affects xenopus laevis morphogenesis and the non-canonical wnt5a/ror2 signalling.	reduced phosphomannomutase 2 activity in man leads to hypoglycosylation of glycoconjugates causing pmm2-cdg, the most common type of congenital disorders of glycosylation. here we show that an antisense morpholino-mediated knockdown of the xenopus laevis phosphomannomutase 2 gene provoked a general underglycosylation in frog embryos, which led to an altered phenotype and reduced glycosylation of wnt5a as member of the non-canonical wnt signalling. loss of function experiments in hemi-sectioned e ...	2015	26141167
evolution of courtship songs in xenopus : vocal pattern generation and sound production.	the extant species of african clawed frogs (xenopus and silurana) provide an opportunity to link the evolution of vocal characters to changes in the responsible cellular and molecular mechanisms. in this review, we integrate several robust lines of research: evolutionary trajectories of xenopus vocalizations, cellular and circuit-level mechanisms of vocalization in selected xenopus model species, and xenopus evolutionary history and speciation mechanisms. integrating recent findings allows us to ...	2015	26138673
3d bio-etching of a complex composite-like embryonic tissue.	morphogenesis involves a complex series of cell signaling, migration and differentiation events that are coordinated as tissues self-assemble during embryonic development. collective cell movements such as those that occur during morphogenesis have typically been studied in 2d with single layers of cultured cells adhering to rigid substrates such as glass or plastic. in vivo, the intricacies of the 3d microenvironment and complex 3d responses are pivotal in the formation of functional tissues. t ...	2015	26138309
distinct functional roles of amphibian (xenopus laevis) colony-stimulating factor-1- and interleukin-34-derived macrophages.	although mϕ represent the most primordial immune cell subsets, the mechanisms governing their functional heterogeneity remain poorly defined. however, it is well established that the csf-1 cytokine contributes to monopoiesis and to this heterogeneity, whereas the unrelated il-34 also binds the csf-1r toward poorly understood immunologic roles. to delineate the molecular and evolutionary basis behind vertebrate mϕ functional heterogeneity, we performed comprehensive transcriptional and functional ...	2015	26136505
sumoylation of the c-terminal domain of dna topoisomerase iiα regulates the centromeric localization of claspin.	dna topoisomerase ii (topoii) regulates dna topology by its strand passaging reaction, which is required for genome maintenance by resolving tangled genomic dna. in addition, topoii contributes to the structural integrity of mitotic chromosomes and to the activation of cell cycle checkpoints in mitosis. post-translational modification of topoii is one of the key mechanisms by which its broad functions are regulated during mitosis. sumoylation of topoii is conserved in eukaryotes and plays a crit ...	2015	26131587
dna-protein crosslink repair.	dna-protein crosslinks (dpcs) are highly toxic dna adducts, but whether dedicated dpc-repair mechanisms exist was until recently unknown. this has changed with discoveries made in yeast and xenopus laevis that revealed a protease-based dna-repair pathway specific for dpcs. importantly, mutations in the gene encoding the putative human homologue of a yeast dpc protease cause a human premature ageing and cancer predisposition syndrome. thus, dpc repair is a previously overlooked genome-maintenance ...	2015	26130008
de novo transcriptome assemblies of rana (lithobates) catesbeiana and xenopus laevis tadpole livers for comparative genomics without reference genomes.	in this work we studied the liver transcriptomes of two frog species, the american bullfrog (rana (lithobates) catesbeiana) and the african clawed frog (xenopus laevis). we used high throughput rna sequencing (rna-seq) data to assemble and annotate these transcriptomes, and compared how their baseline expression profiles change when tadpoles of the two species are exposed to thyroid hormone. we generated more than 1.5 billion rna-seq reads in total for the two species under two conditions as tre ...	2015	26121473
using xenopus to discover new genes involved in branchiootorenal spectrum disorders.	congenital hearing loss is an important clinical problem because, without early intervention, affected children do not properly acquire language and consequently have difficulties developing social skills. although most newborns in the us are screened for hearing deficits, even earlier diagnosis can be made with prenatal genetic screening. genetic screening that identifies the relevant mutated gene can also warn about potential congenital defects in organs not related to hearing. we will discuss ...	2015	26117063
spak and osr1 sensitivity of excitatory amino acid transporter eaat3.	kinases involved in the regulation of epithelial transport include spak (sps1-related proline/alanine-rich kinase) and osr1 (oxidative stress-responsive kinase 1). spak and osr1 are both regulated by wnk (with-no-k(lys)) kinases. the present study explored whether spak and/or osr1 influence the excitatory amino acid transporter eaat3, which accomplishes glutamate and aspartate transport in kidney, intestine and brain.	2015	26112741
structure and gating of the nuclear pore complex.	nuclear pore complexes (npcs) perforate the nuclear envelope and allow the exchange of macromolecules between the nucleus and the cytoplasm. to acquire a deeper understanding of this transport mechanism, we analyse the structure of the npc scaffold and permeability barrier, by reconstructing the xenopus laevis oocyte npc from native nuclear envelopes up to 20 å resolution by cryo-electron tomography in conjunction with subtomogram averaging. in addition to resolving individual protein domains of ...	2015	26112706
benchmarking transcriptome quantification methods for duplicated genes in xenopus laevis.	xenopus is an important model organism for the study of genome duplication in vertebrates. with the full genome sequence of diploid xenopus tropicalis available, and that of allotetraploid x. laevis close to being finished, we will be able to expand our understanding of how duplicated genes have evolved. one of the key features in the study of the functional consequence of gene duplication is how their expression patterns vary across different conditions, and rna-seq seems to have enough resolut ...	2015	26112470
identification and functional characterization of a novel arginine/ornithine transporter, a member of a cationic amino acid transporter subfamily in the trypanosoma cruzi genome.	trypanosoma cruzi, the etiological agent of chagas disease, is auxotrophic for arginine. it obtains this amino acid from the host through transporters expressed on the plasma membrane and on the membranes of intracellular compartments. a few cationic amino acid transporters have been characterized at the molecular level, such as the novel intracellular arginine/ornithine transporter, tccat1.1, a member of the tccat subfamily that is composed of four almost identical open reading frames in the t. ...	2015	26109388
melanopsins: localization and phototransduction in xenopus laevis melanophores.	xenopus laevis melanophores express two melanopsins, opn4x and opn4m. we identified opn4x immunoreactivity throughout the melanophore cytoplasm and in the cell membrane. the strongest immunopositivity for opn4m was observed in the nuclear region, and no labeling was seen in the cell membrane. this immunodistribution suggests opn4x as the functional photopigment. in x. laevis melanophores, light triggers pigment dispersion and clock gene induction at blue wavelength, which maximally activates mel ...	2015	26108966
bh3 domain-independent apolipoprotein l1 toxicity rescued by bcl2 prosurvival proteins.	the potent trypanolytic properties of human apolipoprotein l1 (apol1) can be neutralized by the trypanosome variant surface antigen gene product known as serum resistance-associated protein. however, two common apol1 haplotypes present uniquely in individuals of west african ancestry each encode apol1 variants resistant to serum resistance-associated protein, and each confers substantial resistance to human african sleeping sickness. in contrast to the dominantly inherited anti-trypanosomal acti ...	2015	26108665
structure-activity relationships of bumetanide derivatives: correlation between diuretic activity in dogs and inhibition of the human nkcc2a transporter.	the n-k-cl cotransporters (nkccs) mediate the coupled, electroneutral movement of na+ , k+ and cl- ions across cell membranes. there are two isoforms of this cation co-transporter, nkcc1 and nkcc2. nkcc2 is expressed primarily in the kidney and is the target of diuretics such as bumetanide. bumetanide was discovered by screening ∼5000 3-amino-5-sulfamoylbenzoic acid derivatives, long before nkcc2 was identified in the kidney. therefore, structure-activity studies on effects of bumetanide derivat ...	2015	26101812
investigations of the synergistic enhancement of antimicrobial activity in mixtures of magainin 2 and pgla.	magainins are antimicrobial peptides isolated from the african clawed frog xenopus laevis. they interact with bacterial membranes where they cause channel formation and membrane disruption. when added as a cocktail magainin 2 and pgla are considerably more efficient when compared to the corresponding amounts of individual components. in order to investigate this synergistic interaction of pgla and magainin a number of magainin variants have been prepared and investigated in biological and biophy ...	2016	26099623
melanopsin photoreception in the eye regulates light-induced skin colour changes through the production of α-msh in the pituitary gland.	how skin colour adjusts to circadian light/dark cycles is poorly understood. melanopsin (opn4) is expressed in melanophores, where in vitro studies suggest it regulates skin pigmentation through a 'primary colour response' in which light photosensitivity is translated directly into pigment movement. however, the entrainment of the circadian rhythm is regulated by a population of melanopsin-expressing retinal ganglion cells (mrgcs) in the eye. therefore, in vivo, melanopsin may trigger a 'seconda ...	2015	26095528
herg channel inhibitory daphnane diterpenoid orthoesters and polycephalones a and b with unprecedented skeletons from gnidia polycephala.	the herg channel is an important antitarget in safety pharmacology. several drugs have been withdrawn from the market or received severe usage restrictions because of herg-related cardiotoxicity. in a screening of medicinal plants for herg channel inhibition using a two-microelectrode voltage clamp assay with xenopus laevis oocytes, a dichloromethane extract of the roots of gnidia polycephala reduced the peak tail herg current by 58.8 ± 13.4% (n = 3) at a concentration of 100 μg/ml. by means of ...	2015	26091146
functional characteristics of l1156f-cftr associated with alcoholic chronic pancreatitis in japanese.	although cystic fibrosis is rare in japanese, measurement of sweat cl(-) has suggested mild dysfunction of cystic fibrosis transmembrane conductance regulator (cftr) in some patients with chronic pancreatitis. in the present study, we have investigated the association of cftr variants and chronic pancreatitis in japanese and the functional characteristics of a japanese- and pancreatitis-specific cftr variant, l1156f. seventy patients with alcoholic chronic pancreatitis, 18 patients with idiopath ...	2015	26089335
extraordinary diversity in the origins of sex chromosomes in anurans inferred from comparative gene mapping.	sex determination in frogs (anurans) is genetic and includes both male and female heterogamety. however, the origins of the sex chromosomes and their differentiation processes are poorly known. to investigate diversity in the origins of anuran sex chromosomes, we compared the chromosomal locations of sex-linked genes in 4 species: the african clawed frog (xenopus laevis), the western clawed frog (silurana/x. tropicalis), the japanese bell-ring frog (buergeria buergeri), and the japanese wrinkled ...	2015	26089094
mesodermal origin of median fin mesenchyme and tail muscle in amphibian larvae.	mesenchyme is an embryonic precursor tissue that generates a range of structures in vertebrates including cartilage, bone, muscle, kidney, and the erythropoietic system. mesenchyme originates from both mesoderm and the neural crest, an ectodermal cell population, via an epithelial to mesenchymal transition (emt). because ectodermal and mesodermal mesenchyme can form in close proximity and give rise to similar derivatives, the embryonic origin of many mesenchyme-derived tissues is still unclear. ...	2015	26086331
direct activation of amidohydrolase domain-containing 1 gene by thyroid hormone implicates a role in the formation of adult intestinal stem cells during xenopus metamorphosis.	the t3-dependent anuran metamorphosis resembles postembryonic development in mammals, the period around birth when plasma t3 levels peak. in particular, the remodeling of the intestine during metamorphosis mimics neonatal intestinal maturation in mammals when the adult intestinal epithelial self-renewing system is established. we have been using intestinal metamorphosis to investigate how the organ-specific adult stem cells are formed during vertebrate development. early studies in xenopus laevi ...	2015	26086244
spermidine and ca(2+), but not na(+), can permeate nmda receptors consisting of glun1 and glun2a or glun2b in the presence of mg(2+).	n-methyl-d-aspartate receptors (nmda receptors) are known to be permeable to na(+) and ca(2+) ions. in this study, we tested whether polyamines (putrescine, spermidine, spermine), organic cations found in cells, can permeate nmda receptors expressed in xenopus laevis oocytes and hek293 cells. it was found that polyamines, especially spermidine, can permeate nmda channels expressed from glun1/glun2a or glun1/glun2b activated by glycine and glutamate. furthermore, spermidine and ca(2+) influx thro ...	2015	26086092
determination of alkali-sensing parts of the insulin receptor-related receptor using the bioinformatic approach.	irr (insulin receptor-related receptor) is a receptor tyrosine kinase belonging to the insulin receptor family, which also includes insulin receptor and igf-ir receptor. we have previously shown that irr is activated by extracellular fluid with ph > 7.9 and regulates excess alkali excretion in the body. we performed a bioinformatic analysis of the ph-sensitive potential of all three members of the insulin receptor family of various animal species (from frog to man) and their chimeras with swappi ...	0	26085948
expression, sorting and transport studies for the orphan carrier slc10a4 in neuronal and non-neuronal cell lines and in xenopus laevis oocytes.	slc10a4 belongs to the solute carrier family slc10 whose founding members are the na(+)/taurocholate co-transporting polypeptide (ntcp, slc10a1) and the apical sodium-dependent bile acid transporter (asbt, slc10a2). these carriers maintain the enterohepatic circulation of bile acids between the liver and the gut. slc10a4 was identified as a novel member of the slc10 carrier family with the highest phylogenetic relationship to ntcp. the slc10a4 protein was detected in synaptic vesicles of choline ...	2015	26084360
high yield expression and purification of equilibrative nucleoside transporter 7 (ent7) from arabidopsis thaliana.	equilibrative nucleoside transporters (ents) facilitate the import of nucleosides and their analogs into cells in a bidirectional, non-concentrative manner. however, in contrast to their name, most characterized plant ents act in a concentrative manner. a direct characterization of any ent protein has been hindered due to difficulties in overexpression and obtaining pure recombinant protein.	2015	26080001
kbot55, purified from buthus occitanus tunetanus venom, represents the first member of a novel α-ktx subfamily.	kbot55 is a 39 amino acid peptide isolated from the venom of the tunisian scorpion buthus occitanus tunetanus. this peptide is cross-linked by 3 disulfide bridges and has a molecular mass of 4128.65da. kbot55 is very low represented in the venom and thus represents a challenge for biochemical characterization. in this study, kbot55 has been subjected to a screening on ion channels expressed in xenopus laevis oocytes. it was found that kbot55 targets voltage-gated potassium channels with high aff ...	2016	26079392
identification of amino acids involved in histamine potentiation of gaba a receptors.	histamine is a neurotransmitter involved in a number of physiological and neuronal functions. in mammals, such as humans, and rodents, the histaminergic neurons found in the tuberomamillary nucleus project widely throughout the central nervous system. histamine acts as positive modulator of gabaa receptors (gabaars) and, in high concentrations (10 mm), as negative modulator of the strychnine-sensitive glycine receptor. however, the exact molecular mechanisms by which histamine acts on gabaars ar ...	2015	26074818
recovery capabilities of xenopus laevis after exposure to cadmium and zinc.	the present investigation evaluates the recovery capabilities of xenopus laevis following 12days of exposure to 30μg cdl(-1) and 1000μg znl(-1) alone or mixed, followed by a depuration phase in laboratory conditions. focused endpoints, which were investigated at different times of depuration, are bioaccumulation of cd and zn, micronucleus induction, quantification of metallothioneins (mts), and expression of genes involved in metal toxicity mechanisms. the results show that at the end of the con ...	2015	26073702
molecular polymorphism and divergence of duplicated genes in tetraploid african clawed frogs (xenopus).	genome duplication creates redundancy in proteins and their interaction networks, and subsequent smaller-scale gene duplication can further amplify genetic redundancy. mutations then lead to the loss, maintenance or functional divergence of duplicated genes. genome duplication occurred many times in african clawed frogs (genus xenopus), and almost all extant species in this group evolved from a polyploid ancestor. to better understand the nature of selective constraints in a polyploid genome, we ...	2015	26066830
high incidence of functional ion-channel abnormalities in a consecutive long qt cohort with novel missense genetic variants of unknown significance.	the long qt syndrome (lqts) is a disorder characterized by a prolongation of the qt interval and a propensity to ventricular tachyarrhythmias, which may lead to syncope, cardiac arrest, or sudden death. our objective was to (1) determine the incidence of variants with unknown significance (vus) in a cohort of consecutive lqts patients and (2) to determine the percentage of those with novel missense vus that have demonstrable functional channel abnormalities from a single referral center. we perf ...	2015	26066609
nonclassical mhc-restricted invariant vα6 t cells are critical for efficient early innate antiviral immunity in the amphibian xenopus laevis.	nonclassical mhc class ib-restricted invariant t (it) cell subsets are attracting interest because of their potential to regulate immune responses against various pathogens. the biological relevance and evolutionary conservation of it cells have recently been strengthened by the identification of it cells (invariant vα6 [ivα6]) restricted by the nonclassical mhc class ib molecule xnc10 in the amphibian xenopus laevis. these ivα6 t cells are functionally similar to mammalian cd1d-restricted invar ...	2015	26062996
intracellular microrna profiles form in the xenopus laevis oocyte that may contribute to asymmetric cell division.	asymmetric distribution of fate determinants within cells is an essential biological strategy to prepare them for asymmetric division. in this work we measure the intracellular distribution of 12 maternal micrornas (mirna) along the animal-vegetal axis of the xenopus laevis oocyte using qpcr tomography. we find the mirnas have distinct intracellular profiles that resemble two out of the three profiles we previously observed for mrnas. our results suggest that mirnas in addition to proteins and m ...	2015	26059897
netrin-1 directs dendritic growth and connectivity of vertebrate central neurons in vivo.	netrins are a family of extracellular proteins that function as chemotropic guidance cues for migrating cells and axons during neural development. in the visual system, netrin-1 has been shown to play a key role in retinal ganglion cell (rgc) axon growth and branching at the target, where presynaptic rgc axons form partnerships with the dendrites of tectal neurons. however, the signals that guide the connections between rgc axons and their postsynaptic partners are yet unknown. here, we explored ...	2015	26058786
the structure of a contact-dependent growth-inhibition (cdi) immunity protein from neisseria meningitidis mc58.	contact-dependent growth inhibition (cdi) is an important mechanism of intercellular competition between neighboring gram-negative bacteria. cdi systems encode large surface-exposed cdia effector proteins that carry a variety of c-terminal toxin domains (cdia-cts). all cdi(+) bacteria also produce cdii immunity proteins that specifically bind to the cognate cdia-ct and neutralize its toxin activity to prevent auto-inhibition. here, the x-ray crystal structure of a cdii immunity protein from neis ...	2015	26057799
peptoid-substituted hybrid antimicrobial peptide derived from papiliocin and magainin 2 with enhanced bacterial selectivity and anti-inflammatory activity.	antimicrobial peptides (amps) are important components of the host innate immune system. papiliocin is a 37-residue amp purified from larvae of the swallowtail butterfly papilio xuthus. magainin 2 is a 23-residue amp purified from the skin of the african clawed frog xenopus laevis. we designed an 18-residue hybrid peptide (papma) incorporating n-terminal residues 1-8 of papiliocin and n-terminal residues 4-12 of magainin 2, joined by a proline (pro) hinge. papma showed high antimicrobial activit ...	2015	26053120
usp18 sensitivity of peptide transporters pept1 and pept2.	usp18 (ubiquitin-like specific protease 18) is an enzyme cleaving ubiquitin from target proteins. usp18 plays a pivotal role in antiviral and antibacterial immune responses. on the other hand, ubiquitination participates in the regulation of several ion channels and transporters. usp18 sensitivity of transporters has, however, never been reported. the present study thus explored, whether usp18 modifies the activity of the peptide transporters pept1 and pept2, and whether the peptide transporters ...	2015	26046984
regulation of neuronal high-voltage activated ca(v)2 ca(2+) channels by the small gtpase rhoa.	high-voltage-activated (hva) ca(2+) channels are known regulators of synapse formation and transmission and play fundamental roles in neuronal pathophysiology. small gtpases of rho and rgk families, via their action on both cytoskeleton and ca(2+) channels are key molecules for these processes. while the effects of rgk gtpases on neuronal hva ca(2+) channels have been widely studied, the effects of rhoa on the hva channels remains however elusive. using heterologous expression in xenopus laevis ...	2015	26044639
locomotor corollary activation of trigeminal motoneurons: coupling of discrete motor behaviors.	during motor behavior, corollary discharges of the underlying motor commands inform sensory-motor systems about impending or ongoing movements. these signals generally limit the impact of self-generated sensory stimuli but also induce motor reactions that stabilize sensory perception. here, we demonstrate in isolated preparations of xenopus laevis tadpoles that locomotor corollary discharge provokes a retraction of the mechanoreceptive tentacles during fictive swimming. in the absence of sensory ...	2015	26041033
probing the redox states of sodium channel cysteines at the binding site of μo§-conotoxin gviij.	μo§-conotoxin gviij is a 35-amino acid peptide that readily blocks six of eight tested nav1 subunit isoforms of voltage-gated sodium channels. μo§-gviij is unusual in having an s-cysteinylated cysteine (at residue 24). a proposed reaction scheme involves the peptide-channel complex stabilized by a disulfide bond formed via thiol-disulfide exchange between cys24 of the peptide and a cys residue at neurotoxin receptor site 8 in the pore module of the channel (specifically, cys910 of rat nav1.2). t ...	2015	26039939
an endocannabinoid system is present in the mouse olfactory epithelium but does not modulate olfaction.	endocannabinoids modulate a diverse array of functions including progenitor cell proliferation in the central nervous system, and odorant detection and food intake in the mammalian central olfactory system and larval xenopus laevis peripheral olfactory system. however, the presence and role of endocannabinoids in the peripheral olfactory epithelium have not been examined in mammals. we found the presence of cannabinoid type 1 (cb1) and cannabinoid type 2 (cb2) receptor protein and mrna in the ol ...	2015	26037800
toxicological aspects of photocatalytic degradation of selected xenobiotics with nano-sized mn-doped tio2.	the toxic effects of two selected xenobiotics, bisphenol a (bpa) and atrazine (atz), were evaluated after photocatalytic degradation using nano-sized, mn-doped tio2. undoped and mn-doped tio2 nanoparticles were synthesized. the samples were characterized by x-ray diffractometry (xrd), scanning electron microscopy (sem), uv-vis-diffuse reflectance spectra (drs), x-ray fluorescence spectroscopy (xrf), and bet surface area. the photocatalytic efficiency of the undoped and mn-doped tio2 was evaluate ...	2015	26037099